[media] media: rc: nuvoton: switch attribute wakeup_data to text

Switch attribute wakeup_data from binary to a text attribute.
This makes it easier to handle in userspace and allows to
use the output of tools like mode2 almost as is to set a
wakeup sequence.
Changing to a text format and values in microseconds also
makes the userspace interface independent of the setting of
SAMPLE_PERIOD in the driver.

In addition document the new sysfs attribute in
Documentation/ABI/testing/sysfs-class-rc-nuvoton.

Signed-off-by: Heiner Kallweit <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

Documentation/ABI/testing/sysfs-class-rc-nuvoton

···
+What:		/sys/class/rc/rcN/wakeup_data
+Date:		Mar 2016
+KernelVersion:	4.6
+Contact:	Mauro Carvalho Chehab <[e-mail]>
+Description:
+		Reading this file returns the stored CIR wakeup sequence.
+		It starts with a pulse, followed by a space, pulse etc.
+		All values are in microseconds.
+		The same format can be used to store a wakeup sequence
+		in the Nuvoton chip by writing to this file.
+
+		Note: Some systems reset the stored wakeup sequence to a
+		factory default on each boot. On such systems store the
+		wakeup sequence in a file and set it on boot using e.g.
+		a udev rule.

drivers/media/rc/nuvoton-cir.c

···
 	}
 }
 
-static ssize_t wakeup_data_read(struct file *fp, struct kobject *kobj,
-				struct bin_attribute *bin_attr,
-				char *buf, loff_t off, size_t count)
+static ssize_t wakeup_data_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
 {
-	struct device *dev = kobj_to_dev(kobj);
 	struct rc_dev *rc_dev = to_rc_dev(dev);
 	struct nvt_dev *nvt = rc_dev->priv;
-	int fifo_len, len;
+	int fifo_len, duration;
 	unsigned long flags;
+	ssize_t buf_len = 0;
 	int i;
 
 	spin_lock_irqsave(&nvt->nvt_lock, flags);
 
 	fifo_len = nvt_cir_wake_reg_read(nvt, CIR_WAKE_FIFO_COUNT);
-	len = min(fifo_len, WAKEUP_MAX_SIZE);
-
-	if (off >= len) {
-		spin_unlock_irqrestore(&nvt->nvt_lock, flags);
-		return 0;
-	}
-
-	if (len > count)
-		len = count;
+	fifo_len = min(fifo_len, WAKEUP_MAX_SIZE);
 
 	/* go to first element to be read */
-	while (nvt_cir_wake_reg_read(nvt, CIR_WAKE_RD_FIFO_ONLY_IDX) != off)
+	while (nvt_cir_wake_reg_read(nvt, CIR_WAKE_RD_FIFO_ONLY_IDX))
 		nvt_cir_wake_reg_read(nvt, CIR_WAKE_RD_FIFO_ONLY);
 
-	for (i = 0; i < len; i++)
-		buf[i] = nvt_cir_wake_reg_read(nvt, CIR_WAKE_RD_FIFO_ONLY);
+	for (i = 0; i < fifo_len; i++) {
+		duration = nvt_cir_wake_reg_read(nvt, CIR_WAKE_RD_FIFO_ONLY);
+		duration = (duration & BUF_LEN_MASK) * SAMPLE_PERIOD;
+		buf_len += snprintf(buf + buf_len, PAGE_SIZE - buf_len,
+				    "%d ", duration);
+	}
+	buf_len += snprintf(buf + buf_len, PAGE_SIZE - buf_len, "\n");
 
 	spin_unlock_irqrestore(&nvt->nvt_lock, flags);
 
-	return len;
+	return buf_len;
 }
 
-static ssize_t wakeup_data_write(struct file *fp, struct kobject *kobj,
-				struct bin_attribute *bin_attr,
-				char *buf, loff_t off, size_t count)
+static ssize_t wakeup_data_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t len)
 {
-	struct device *dev = kobj_to_dev(kobj);
 	struct rc_dev *rc_dev = to_rc_dev(dev);
 	struct nvt_dev *nvt = rc_dev->priv;
 	unsigned long flags;
-	u8 tolerance, config;
-	int i;
+	u8 tolerance, config, wake_buf[WAKEUP_MAX_SIZE];
+	char **argv;
+	int i, count;
+	unsigned int val;
+	ssize_t ret;
 
-	if (off > 0)
-		return -EINVAL;
+	argv = argv_split(GFP_KERNEL, buf, &count);
+	if (!argv)
+		return -ENOMEM;
+	if (!count || count > WAKEUP_MAX_SIZE) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	for (i = 0; i < count; i++) {
+		ret = kstrtouint(argv[i], 10, &val);
+		if (ret)
+			goto out;
+		val = DIV_ROUND_CLOSEST(val, SAMPLE_PERIOD);
+		if (!val || val > 0x7f) {
+			ret = -EINVAL;
+			goto out;
+		}
+		wake_buf[i] = val;
+		/* sequence must start with a pulse */
+		if (i % 2 == 0)
+			wake_buf[i] |= BUF_PULSE_BIT;
+	}
 
 	/* hardcode the tolerance to 10% */
 	tolerance = DIV_ROUND_UP(count, 10);
···
 			       CIR_WAKE_IRCON);
 
 	for (i = 0; i < count; i++)
-		nvt_cir_wake_reg_write(nvt, buf[i], CIR_WAKE_WR_FIFO_DATA);
+		nvt_cir_wake_reg_write(nvt, wake_buf[i], CIR_WAKE_WR_FIFO_DATA);
 
 	nvt_cir_wake_reg_write(nvt, config, CIR_WAKE_IRCON);
 
 	spin_unlock_irqrestore(&nvt->nvt_lock, flags);
 
-	return count;
+	ret = len;
+out:
+	argv_free(argv);
+	return ret;
 }
-
-static BIN_ATTR_RW(wakeup_data, WAKEUP_MAX_SIZE);
+static DEVICE_ATTR_RW(wakeup_data);
 
 /* dump current cir register contents */
 static void cir_dump_regs(struct nvt_dev *nvt)
···
 			     NVT_DRIVER_NAME "-wake", (void *)nvt))
 		goto exit_unregister_device;
 
-	ret = device_create_bin_file(&rdev->dev, &bin_attr_wakeup_data);
+	ret = device_create_file(&rdev->dev, &dev_attr_wakeup_data);
 	if (ret)
 		goto exit_unregister_device;
 
···
 {
 	struct nvt_dev *nvt = pnp_get_drvdata(pdev);
 
-	device_remove_bin_file(&nvt->rdev->dev, &bin_attr_wakeup_data);
+	device_remove_file(&nvt->rdev->dev, &dev_attr_wakeup_data);
 
 	nvt_disable_cir(nvt);